What is a Sandwich?

I just had a spirited conversation with a friend on whether a hot dog or a wrap was a sandwich.  We exchanged view points and videos. 

So with great fanfare, we are going to tackle the question of what is a sandwich.  According to Merriam-Webster Dictionary, a sandwich is defined as 

• two or more slices of bread or a split roll having a filling in between, 

• one slice of bread covered with food; or 

• something resembling a sandwich

Putting aside the third definition which does not offer much help, are the following sandwiches, 

• Hot Open Turkey

• Turkey Wraps

• Cheeseburger

• Hot Dog

• Taco

• Ice Cream Sandwich (ice cream between two cookies)

It seems to me that the dictionary requires some form of bread but is that really necessary.

I found this great chart helps me understand where I stand. I will skip the ridiculous thought process that sandwiches are those items that have sandwich in their name like a hot open turkey sandwich, ice cream sandwich and a Pigeon and worm sandwich.

I fall into the Ingredient Purist category so I have to say that I find a BLT, Sub and Chicken Wraps to be sandwiches. But I do not think hot dogs or ice cream sandwiches are sandwiches. Let alone, a pop tart can never be a sandwich in my world.

What do you think?